<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta
      name="viewport"
      content="width=device-width, initial-scale=1, maximum-scale=1, minimum-scale=1, user-scalable=no"
    />
    <title>Document</title>
    <style>
      * {
        margin: 0;
        padding: 0;
      }
      .box1 {
        float: left;
        width: 50vw;
        height: 200px;
        background-color: yellowgreen;
      }
      .box2 {
        float: left;
        width: 50vw;
        height: 200px;
        background-color: greenyellow;
      }
      .box3 {
        float: left;
        width: 40vw;
        height: 200px;
        background-color: greenyellow;
      }
    </style>
  </head>
  <body>
    <div class="box1"></div>
    <div class="box2"></div>
    <div class="box3"></div>
  </body>
</html>
